Thanks for creating this task. It would be even nicer if the description mentioned *all* the research that is needed or ongoing before the big red switch for T49832 is turned. Just titles would suffice. With its current definition the task is too vague, it may range from few hours of work to add some graph for existing data to years of work for entire university departments. :)

For instance, per-country errors %, per-project errors %, per-country navtiming, per-project navtiming, editor retention, editor activation, bounce rate, number or link clicks, ...? (Some unlikely, e.g. bounce rate.)